Carbon dynamics, regeneration and forest normality in temperate Himalayan fir-spruce forest ecosystem, India

Aim: To assess the carbon dynamics, regeneration status and forest normality of Fir-Spruce forest in the Sirmaur district of Himachal Pradesh. Methodology: The study was conducted in the Fir–Spruce (Selection) working circle at elevations ranging from 2,150 to 3,600 m asl. Ten compartments were randomly selected based on crop composition and density. Tree measurements (DBH and height) were used to quantify volume, biomass, and carbon stock following IPCC and FRI standard methodologies, while regeneration was assessed using systematic quadrat sampling and Chacko’s methods. Results: Among the compartments, RF 9 Pajoga C-4e recorded the highest growing stock (762.94 m3 ha-1), biomass (588.93 t ha-1), carbon stock (294.47 t ha-1), and carbon mitigation potential (1079.71 t ha-1). Overall, the Fir–Spruce forest had a growing stock of 611.95 m3 ha-1, biomass of 466.30 t ha-1, carbon stock of 233.15 t ha-1, and mitigation potential of 854.88 t CO2 ha-1. Among species, Picea smithiana exhibited the highest growing stock (420.16 m3 ha-1), biomass (305.17 t ha-1), and carbon stock (152.59 t ha-1), followed by Abies pindrow. Regeneration percentage was highest in RF 8 Baer Jamoli C-2a (50.00%) and lowest in RF 5 Narh C-3 (13.89%). Species wise, regeneration was highest in Picea smithiana (21.67%), with lower values in Abies pindrow, Quercus dilatata, Q. semecarpifolia, Rhododendron arboreum and Q. leucotrichophora and absent in Pinus wallichiana and Cedrus deodara. Interpretation: The prevalence of mature and over-mature trees, along with insufficient regeneration, highlights critical management challenges in these forests under the selection system, requiring targeted silvicultural interventions to restore forest normality. Key words: Carbon stock, Forest normality, Picea smithiana, Regeneration status, Stocking level, Selection system